【程序61】
题目：打印出杨辉三角形（要求打印出10行如下图）
1.程序分析：
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
2.程序源代码：
main()
{
int i, j;
int a[10][10];
printf("\n");
for(i=0; i<10; i++)
{
a[i][0] = 1;
a[i][i] = 1;
}
for(i=2;i<10;i++)
for(j=1;j<10; j++)
a[i][j] = a[i-1][j-1] + a[i-1][j];
for(i=0; i<10; i++)
{
for(j=0;j<=i;j++)
printf("%5d", a[i][j]);
printf("\n");
}
}
【程序62】
题目：学习putpixel画点。
1.程序分析：
2.程序源代码：
#include "stdio.h"
#include "graphics.h"
main()
{
int i, j, driver = VGA, mode = VGAHI;
initgraph(&driver, &mode, "");
setbkcolor(YELLOW);
for(i=50; i<=230; i+=20)
for(j=50; j<=230; j++)
putpixel(i, j, 1);
for(j=50; j<=230; j+=20)
for(i=50; i<=230; i++)
putpixel(i, j, 1);
}
【程序63】
题目：画椭圆ellipse
1.程序分析：
2.程序源代码：
#include "stdio.h"
#include "graphics.h"
#include "conio.h"
/* 欢迎访问 C++Builder研究 - www.ccrun.com */
main()
{
int x = 360, y = 160, driver = VGA, mode = VGAHI;
int num=20, i;
int top, bottom;
initgraph(&driver, &mode, "");
top = y - 30;
bottom = y - 30;
for(i=0; i<num; i++)
{
ellipse(250, 250, 0, 360, top, bottom);
top -= 5;
bottom += 5;
}
getch();
}
【程序64】
题目：利用ellipse and rectangle 画图。
1.程序分析：
2.程序源代码：
#include "stdio.h"
#include "graphics.h"
#include "conio.h"
main()
{
int driver = VGA, mode = VGAHI;
int i, num = 15, top = 50;
int left = 20, right = 50;
initgraph(&driver, &mode, "");
for(i=0; i<num; i++)
{
ellipse(250, 250, 0, 360, right, left);
ellipse(250, 250, 0, 360, 20, top);
rectangle(20 - 2 * i, 20 - 2 * i, 10 * (i + 2), 10 * (i + 2));
right += 5;
left += 5;
top += 10;
}
getch();
}
【程序65】
题目：一个最美丽的图案。
1.程序分析：
2.程序源代码：
#include "graphics.h"
#include "math.h"
#include "dos.h"
#include "conio.h"
#include "stdlib.h"
#include "stdio.h"
#include "stdarg.h"
#define MAXPTS 15
#define PI 3.1415926
strUCt PTS
{
int x, y;
};
/* 63 63 72 75 6E 2E 63 6F 6D */
double ASPectRatio = 0.85;
void LineToDemo(void)
{
struct viewporttype vp;
struct PTS points[MAXPTS];
int i, j, h, w, xcenter, ycenter;
int radius, angle, step;
double rads;
printf(" MoveTo / LineTo Demonstration" );
getviewsettings( &vp );
h = vp.bottom - vp.top;
w = vp.right - vp.left;
xcenter = w / 2; /* Determine the center of circle */
ycenter = h / 2;
radius = (h - 30) / (AspectRatio * 2);
step = 360 / MAXPTS; /* Determine # of increments */
angle = 0; /* Begin at zero degrees */
for(i=0; i<MAXPTS; i++)
{
rads = (double)angle * PI / 180.0; /* Convert angle to radians */
points[i].x = xcenter + (int)( cos(rads) * radius );
points[i].y = ycenter - (int)( sin(rads) * radius * AspectRatio );
angle += step; /* Move to next increment */
}
circle( xcenter, ycenter, radius ); /* Draw bounding circle */
for(i=0; i<MAXPTS; i++)
{
for(j=i; j<MAXPTS; j++)
{
moveto(points[i].x, points[i].y); /* Move to beginning of cord */
lineto(points[j].x, points[j].y); /* Draw the cord */
}
}
}
main()
{
int driver, mode;
driver = CGA; mode = CGAC0;
initgraph(&driver, &mode, "");
setcolor(3);
setbkcolor(GREEN);
LineToDemo();
}
【程序66】
题目：输入3个数a, b, c，按大小顺序输出。
1.程序分析：利用指针方法。
2.程序源代码：
/*pointer*/
main()
{
int n1, n2, n3;
int *pointer1, *pointer2, *pointer3;
printf("please&n